This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form visually contains 山 (mountain) and 言 (speech), but the original semantic or phonetic role of these components is unclear.
With 山 (mountain) over 言 (speech), imagine words echoing off a mountain, but the meaning remains unclear.
For ギン, picture a mountain echo that sounds like a silver bell: gin -> ギン, though the meaning is uncertain.